Process of making filtration and decolorizing adsorbents



. Patented May 7, 1929. n

UNITED STATES 1,111,504- PATENT- OFFICE.

HAROLD '1. MAITLAND, OF SHARON HILL, PENNSYLVANIA, ASSIGNOR TO SUN 01LCOMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF JERSEY.

PROCESS OF MAKING FILTRATION AND DECOLORIZING ADSORBENTS.

No Drawing.

water glass to a free flowing liquid, dissolve ammonium aluminum sulfatein water and mix the two solutions. A temperature above normal assists.in precipitation. The alum solution may be added gradually, preferablyby spraying, so as to secure an intimate admixture, and with agitation;producing a finer precipitate. The precipitate should be boiled in itsfiltrate until the reaction is complete. The product is washed free ofsalts easily soluble in water, and dehydrated at 500 to 1000 F. Thereaction is believed to be as follows:

ater glass, 4Na Si,O,+alummum ammonium sulfate and water ofcrystallization 10H O ortho silicic. acid, 16H,SiO,i+ aluminum hydroxid,Al (OH) 6 sodium sulfate,

The sodium sulfate washes out, while the ammonia goes off as a gas.Water is also driven off, successivel ,convertin the'ortho silicic acidto meta si icic acid, 40 then to adsorptive SiO,. 4

The resultantproduct is a white compound, hard, dry and porous, andadsorptive, selective and active with respect to coloring matter inoils.

Instead of using ammonium aluminum sulfate, I may use aluminum sulfate,givlng, it is believed, the following reaction:

S10 and A highly important characteristic of my product is that it maybe reclaimed, by reheating at the temperature of dehydration, withoutloss of efficiency. I have so reclaimed and reused the product agreatnu-mwhich comprises intimately mixing an amj Application filedFebruary 6, 1924. Serial No. 691,026.

ber of times, without any measurable loss whatever in efficiency.Therefore, although my new adsorbent is not expensive to produce, theoriginal cost-is a factor of little, if any, importance.

Where, in the claims, I specify material containing Al (SO I mean toinclude ammonium aluminum sulfate as well as aluminum sulfate. Havingnow fully described my invention, what Iclaim and desire. to protect byLetters Patent is 1. The process of making the herein describediiltration and decolorizing medium, compr sing reacting a solublesilicate with ammonium aluminum sulfate and dehydratmg.

2. The process of-making the herein described filtration anddecolorizing medium.

which comprises gradually adding to a soluble silicate, materialcontaining Al,(SO,),,

with agitation, boiling, washin out the solu- .-ble salts, anddehydratingat etween 500 and 1000 F.

3. The process of making the herein described filtration anddecolorizing medium "which comprises gradually adding to a solublesilicate ammonium aluminum sulfate, with agitation, boiling, washing outthe soluble salts, and drying.

4. The process of making the herein described filtration anddecolorizing medium which comprises graduallyadding to a solublesilicate ammonium aluminum sulfate with agitation, boiling, washin outthe soluble salts, and dehydrating at between 500 and 1000 F. 1

5. The process of making a composition of meta silicic acid and aluminumhydroxide monium .aluminum salt with a water glass solution to form acompound of ortho silicic acid and aluminum hydroxide and dehydratingltoform an adsorptive compound of silicic an ydride and aluminum hydroxide.

6. The process of making a composition of meta silicic acid and aluminumhydroxide which comprises'intimately mixing with a soluble silicateammonium aluminum sulphate, boiling until the reaction is substantiallycomplete, allowing the ammonium to escape and washing out the sodiumsulfate, and dehydrating at between 500 and 1000 F.

7 The process of making a composition of meta silicic acid and aluminumhydroxide which comprises adding an ammonium aluminum salt to a waterglass solution, with agitation, to form a compound of ortho silieic acidand aluminum hydroxide and dehydrating to form an adsorptive compound ofsilicic anhydride and aluminum hydroxide.

8. The process of making a composition of meta silicic acid and aluminumhydroxide which comprises adding to a soluble silicate ammonium aluminumsulphate, with agitation, boiling imtil the reaction is substantiallycomplete, allowing the ammonium to escape and washing out the sodiumsulfate, and dewhich comprises reacting, a soluble silicate withmaterial containing: AIASOQ, and dehydratin; at between 500 and 1000 F.

In testimony of which inrention, I have hereunto set my hand, atNorwood, Penna, on this first day of February, 1924.

HAROLD T. MAITLAND;

